Editor’s note: This article was originally published June 3, 2014

I’m used to following the black stripe on the bottom of a man-made pool five days a week, but swimming outside the lines, in the ocean, cranks up the fun even more.

I got to do a lot of that during a recent trip to the big island of Hawaii. Besides logging 23 scuba dives off the live-aboard dive boat the Kona Aggressor II, I did a lot of just plain swimming, including three early morning swims in the same bay where the Ironman World Championship takes place.

The best swim, though? Leaping off the dive boat one afternoon alongside a pod of wild spinner dolphins.

It’s kind of spooky at first, swimming in water so deep and blue that it fades to infinity. You can’t see the bottom - it’s hundreds of feet deep - and you’re not sure what might come swimming up out of it. But once you settle in, it’s comforting, like Mother Nature is cradling you in her arms.

I’d been sitting on the back of the dive boat, watching the dolphins for 15 minutes or so, debating if I should get in or not. When one of the dive masters jumped in, I tagged along. Then another dive master joined us. We swam out a few hundred yards but lost sight of the dolphins. I kept looking down into the blue. All I could see was shafts of light flickering into the depths.

Then a couple of folks back on the boat pointed us in the right direction. We swam out a little more, and finally I spotted them - a group of 30 or more dolphins, swimming about 20 feet down and not far away. A few rolled over and gazed up at us. Periodically, three or four rose to the surface, arching and spinning out of the water. They didn’t speed away; I’m pretty sure they slowed down so they could check us out as we swam above them. They chirped and clicked, and I tried to talk dolphin to them.

After 10 or 15 minutes, they moved on, leaving me blissed out by the experience.

I swam back to the boat, doing a series of dolphin kicks to show my appreciation.